Argonne National Laboratory

Slouching Towards Exascale

TitleSlouching Towards Exascale
Publication TypeJournal Article
Year of Publication2009
AuthorsLusk, EL
JournalInternational Journal of High Performance Computing
Date Published10/2009
Other NumbersANL/MCS-P1628-0509

Let us speculate about how we will program exascale machines. Some believe that the current �standard� of MPI plus a venerable sequential language (Fortran, C, or C++) will become as abruptly obsolete as the vector Fortran compilers of the 1970s. While it is exciting to contemplate an ab initio redesign of the HPC software infrastructure, experience tells us that large-scale software (and HPC software is now very large scale) requires a migration path that consists of incremental steps during which only some parts change at a time. Indeed, as scalability forced vectorization to give way to message
passing, Fortran changed a little but was not replaced by Ada.